Prev Med Flashcards

Question

observational studies

Answer 1

study wider range of exposure than experimental studies; studies causes, tx, prevention

Answer 2

when little info is known about dz --> find potential associations (hypothesis); objective = estimate dz freq; variables examined = person, place, time (who/where/when = affected?) vs when enough info of dz = done --> answers "why"/cause of associations and additional questions about dz --> new data (why/how pop = affected?)

Answer 3

case report/series, cross sectional studies, ecological studies

Answer 4

single occurrence of incident, reports new/unique findings (new dz, adverse rxn, possible link b/w exposure, tx outcome) vs report on characteristics of a group of ppl w/ certain dz, no comparison group --> just look at 1 group; can also be based on 1 person

Answer 5

ID new clinical issues that lead to hypothesis, educational vs depends on avail and accuracy of data; cases = not generalizable; not based on systemic studies; no comparison group; can't make tx decisions

Answer 6

exposure and dz status w/in well defined pop = measured at one point in time --> one time assessment (surveys/questionnaire, lab tests, physicals); compare dz prevalence b/w those exposed and not exposed

Answer 7

cheap and quick to conduct, outcomes and risk factors = assessed, good generalizability vs difficult to determine temporal relationship b/w exposure and dz, may have high prevalence from long duration cases

Answer 8

look for one time frame, no f/u, no intervention, only analyze prevalence, can ID risk factors and dz they studied

Answer 9

studying freq of characteristic and outcome in a pop, not individual or location; often uses scatter plots or Pearson correlation coefficients

Answer 10

easy to do at global lvl --> give quick answers to group phenomena vs ecological fallacy --> apply findings of pop to individual

Answer 11

case control studies, cohort studies

Answer 12

examine groups based on dz status (dz'ed vs control group) --> follow those 2 groups --> past exposures determined in each group; uses indirect measure of risk --> no incidence measured --> use odds ratio vs examine groups w/ or w/o specific exposure in pop w/o disease at beginning of study

Answer 13

good for rare dzs or that have long indux and latent periods; can eval mult exposures, quick and cheap, small sample size = okay vs investigates only 1 dz outcome, not good for rare exposures, can't directly determine incidence rates or temporal relationship b/w exposure and dz, vulnerable to bias b/c retrospective (recall bias)

Answer 14

sample should reflect all cases in one pop, should not be selected b/c of exposure vs comparable to cases in every way except they don't have dz --> must be chosen independent of exposure

Answer 15

examine cohorts from the past to present; cheaper, faster, good for dzs w/ latent period, past exposure data = inadequate vs examine cohorts from the present to future; more expensive, slower, not good for dzs w/ latent period, better exposure data, less bias

Answer 16

based on exposure status and follow them, pick a well defined pop --> do questionnaires, lab tests, physicals, procedures, existing records to gather data

Answer 17

directly determines incidence and risk, relationship b/w exposure and dz (better if exposure = rare), follows logic of clinical question, vs needs large sample size, long time to complete, not good for rare dzs, expensive, validity affected by bias d/t subject attrition and loss to f/u

Answer 18

study pop --> current tx (control) or new tx (experimental) --> improve or not improve for both

Answer 19

researcher takes large sample size and uses random assignment to divide them into smaller groups, subjects = blinded to their group membership --> 1 group w/ real med, other group w/ placebo

Answer 20

randomization = ethical when no compelling reason to believe either of randomly allocated txs = better than the other

Answer 21

investigating a measure that prevents dz vs investigating a measure that tx dz vs tx given to individual vs tx given to group vs planned reversal of experimental and control group throughout trial --> each person has own control vs everyone has same study tx vs each group has tx consisting of one component vs each group has tx consisting of 2+ components --> answers more research questions

Answer 22

Hypothesis → participant recruitment → participants allocated to groups → participants’ outcome mentored → rates of outcomes are compared → conclusions and implications

Answer 23

risk of developing dz over time; same as incidence

Answer 24

measures b/w exposure and dz that are compared to risk --> represent diff concepts of risk or diff magnitude of risk

Answer 25

diff in risk b/w exposed and unexposed group: incidence in exposed minus incidence in unexposed; also use 2x2 table. exposure = NOT assoc w/ dz vs dec in dz risk --> protective vs inc in dz risk --> harmful

Answer 26

compares incidence in exposed to unexposed --> incidence in exposed/incidence in unexposed; also use 2x2 table. exposure NOT assoc w/ dz vs exposure assoc w/ inc risk of dz vs exposure assoc w/ dec risk of dz

Answer 27

compares odds of case being exposed to odds of control being exposed --> odds case exposed/odds control exposed. dz = NOT assoc w/ exposure vs exposure --> inc odds of dz vs exposure --> dec odds of dz

Answer 28

excess risk assoc w/ exposure compared to control vs how much risk = reduced in experimental group to control group

Answer 29

investigators won't know which tx groups will receive vs participants, investigators, analysts don't know GROUP MEMBERSHIP

Answer 30

how well the intervention worked between assigned groups, irrespective of participant adherence to control/intervention vs compares outcomes of those who did or did not receive treatment, regardless of assigned group (cross-over); loss of randomization

Answer 31

no intervention; Hawthorne effect - pts have tendency to change behavior when they are target of interest vs compares expt'l tx to known tx vs compares expt'l tx to placebo

Answer 32

officially notifies investigators and drops out of study vs participant stops or modifies assigned treatment without notifying investigators --> do compliance checks to elim vs control group does intervention

Answer 33

number of patients needed to treat to prevent one patient from having an adverse event over a predefined period of time vs number of patients needed treat for one patient to experience an adverse event.

Answer 34

qualitatively answer a single, focused question by summarizing original research vs use statistical methods to combine results of individual studies and provide a quantitative answer within the context of a systematic review; includes insignificant data

Answer 35

answers single focused question, qualitative vs publication bias --> excludes nonsignificant findings, unpublished data, grey literature/ fugitive literature, disagreement on findings

Answer 36

adeq sample size/power, detect tx complications and effectiveness, quantitative vs publication bias, few studies --> high risk of false neg; doesn't include biology of disease or clinical experience

Answer 37

studies answer the same question --> answers may differ by only chance vs studies answer diff questions but form a fam of studies answer similar question; studies = considered a random sample

Answer 38

Shows the point estimate of effectiveness and confidence interval for each study in the review; values to left of null line --> favor expt'l group, values to right of null line --> favor control group

Answer 39

minimum set of items for reporting in systematic reviews and meta-analyses

Answer 40

Encourage releasing all results, registration for all clinical trials, Cochran collaborators. Funnel plots can assess the bias

Answer 41

Pt, intervention, comparison (other tx, placebo), outcome

Answer 42

relative risk, attributable risk vs odds ratio vs NNT, NNH, ARR, RRR

Answer 43

reporting results: consolidated standards of reporting trials